If you have an EFI Bios you can boot from a GPT Volume/Disk. Using Vista SP1 or Some of the server variants. However there very limited options for PC motherboards with EFI compatibility and you'll have to bug support to get it too as those bioses are typically in beta or experimental state and unpublished.

Or you can buy an intel based Mac.

Please note: If you boot off a non-GPT disk 
(<2TB) many windows variants can read and write to GPT disks as a non-boot volume.

Actually i hav ethe GA-X48-DQ6 motherboard with 4x1TB seagate drives and raid-0, all run off the onboard raid controller.

Windows vista ultimate 64-bit runs flawlessly on a 4TB single ntfs partition.

I can't wait for the hilarity that will result when the h4rdc0r3 gamers RAID0 these on their crappy little onboard controllers and find out the BIOS refuses to boot off a volume > 2GB, and no a partition will not solve it. :)